Thermally-controlled circuit interrupter



1,499,429 E. R. STOEKLE THERMALLY CONTROLLED CIRCUIT INTERRUPTER .Filed May 5, 1920 2 Sheets-Sheet l July a Ell ailllllllsl l 1 .ills

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July 1, 1924. 1,499,420

E. R. STOEKLE THERMALLY CONTROLLED CIRCUIT INTERRUPTER Filed May 5. 1920 2 Sheets-Sheet 2 i.lll... I

its individual elements constructe Patented July l, 1924.

UNITED STATES PATENT carica.

ERWIN R.' STOEKLE, 0F MILWAUKEE, WISCONSIN, ASSIGNOB TD TEE BUTLER-HAI- MER MFG. C0., F MILWAUKEE, WISCONSIN, A CORPORATION 0F WISCONSIN.

THERMALLY-OONTROLLED CIRCUIT INTERRUPTEB.

Application med Hay 3,

T o all who/m. t may @071.09m

Be it known that I, EawIN R. STOEKLE, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented new and useful Improvements in Thermally-Controlled Circuit Interrupters, of which the following is a full, clear, concise, and exact description, reference bein had to the accompanying drawing, forming a part of this specification.

This invention relates to thermally controlled circuit interrupters.

More particularly the invention relates to circuit interrupters of the type disclosed and claimed in my co-pending application, Serial No. 358,601, filed February 14, 1920, such type of circuit interrupter comprising a container, preferably glass, and a conductor therein which is fluid at working temperatures, and adapted under thermic inuence to be subjected to action of a lluid under pressure for effecting electrical discontinuity thereof.

The present invention has among its objects to provide a simple, rugged and durable embodiment of such circuit interrupter which may be advantageously used for various urposes and especially as an overload circuit breaker.

Another object is to provide a circuit interrupter of the aforesaid type with associated means to influence the responsiveness thereof within a given range of thecontrolling thermic changes.

Another object is to rovide a circuit breaker of the aforesaid c aracter with associated means to diil'erentlyA influence the responsiveness thereof within different ran es of the controllin thermic changes to ren er the same of the inverse time element t e.

ylilnother object is'to provide a self contained circuit interrupter of the aforesaid type wherein the parts are particularly designed tc promote standardization thereof and of the parts to be associated therewith and wherein the parts are designed for ready calibration. r

Another Objectis that of providin a circuit interrupter of the aforesaid ty e aving and arranged to facilitate assembly and installa- 1920. Serial No. 378,400.

tion and also repair and replacement when necessary.

Other objects and advantages will hereinafter appear.

In the accompanying drawing, wherein is illustrated an embodiment of the invention,

Figure l is a vertical sectional illustration thereof;-

Figure 2 is a front elevational view thereof; while,

Figure 3 is a bottom plan view, partly in section, of the same. j

Referringto the drawing, the same illustrates a thermally responsive circuit control element 5, a heatin coil 6 arranged to surround an intermecllate portion of said element 'and a thermally and electricall insulating support 7 for said element an said coil, said j support being mounted upon a suitable insulating panel 8.

The circuit control element is preferably of the type disclosed and claimed in my copending application aforementioned, and includes a hermetically tight container composed of insulating material and comprisin an enlarged bulb 9 having an axially aligne and restricted tubular extension l() therebelow. Electrodes ll and l2 are sealed within the outer ends ofsaid bulb and said extension respectively and arranged to I enetrate material distances toward one anotl er within the container. Said electrodes are normally electrically connected by a quantity of mercury 13 or other vaporizable liquid conductor which fills said extension and rises an appreciable distance within the bulb. The remaining space within the container is preferably evacuated to reduce the hydrostatic pressure upon the mercury column and also to remove any gaseous matter which might react unfavoraily upon the enl osed conductive parts during operation. owever, such space might optionally be filled with an electrically inert and non-oxidizing as whereas hermetic closure of such space 1s not essential.

Said tubular extension is provided with an interiorly enlarged portion 14 preferabl located at a material distance below the bul 9 and adapted to include an increased bulk of mercury. Upon a predetermined rise in temperature of said bulk of mercury, as by passage through the heating coil 6 of curflOES rent in excess of a predetermined value, said mercury becomes vaporized whereu on the consequent expansion of the liberate vapor serves to drive the liquid mercury located thereabove out of the .intermediate ortion of the tubular extension 10 and .into t e bulb 9 thereby interrupting the electrical continuity of the mercury column and thus interruting circuit between the electrodes 11 an 12. v

The inner diameter of the tubular extension is so restricted that the capillar action between the liquid mercury and t e sides of said passage is sulicient to prevent reilux ofthe liquid mercury within said extension and consequent restoration of electrical continuity of the column so long as a predetermined vapor pressure persists within the enlarged portion 14 of the passage. However, upon a predetermined cooling of the vapor Within such intermediate chamber the weight ofthe mercury column located thereabove is suicient to overcome both the capillary action and the vapor pressure, whereupon liquid mercury flows back within the tubular extension and reunites with the mercu which remains in the lower portion of sai extension for 11e-establishment of the interru ted circuit. In practice the upper electro e 11 is preferably offset laterall out of ali ent with. the axis of the tu ular extension 10 thereby eliminating` or substantially reducing the tendency toward the formatlon of an arc during the aore-described circuit interruption.

The support 7 is substantially of bilaterally symmetrical contour and in general cylindrical, bein divided along a vertical plane into simi ar and interchangeable sections 15 and 16, having adjacent faces adapted to abut one another accurately throughout a major portion of their common extent and bein in practice rigidly clamped together. he assembled support is axiall provided with a. multi-diameter bore exten ing therethrough and adapted to contain and support the circuit control element 5 and the heating coil 6 in suitable operative relation to one another, said bore appearing in the` separate support section as a pair of registering semi-circular grooves oivarying diameter.

The upper portion of the bore is relativley large to receive the enlarged bulb 9 of the element 5 and is provided with an annular shoulder v17 to co-operate with the lower "portion of said bulb for direct support of said element. The portion of said bore below said shoulder is restricted to conform approximately to the size of the tubular extension 1() located therein. However; said restricted portion ofthe bore is again enlarged at a point below said shoulder 17 to provide a space to contain said heating coil 6, said second enlarged portion being provided with upper and lower annular shoulders 18 and 19 for supportin and maintaining said coil in suitable re ation to the enlarged portion 14 of said passage. The portion of said bore located below the said shoulder 19 is again restricted to conform approximately to the diameter of the tubular extension.

The su port 7 ismedially provided with a pair o parallel passages 20 and 21 extending at ri ht-angles'to the axis of the support and isplaced laterally from said axis, being referably located in the same horizontal llane, portions of said passages being included in each of the support sections. Said passages are adapted to receive a pair of elongated clamping studs 24 and 25 having for securing the sections of the support in vassembled relation, said studs also providing for securement of the assembled support upon the panel 8 in a relation of two point suspension.

Each of said support sections is further provided with a pair of counter-bored passages 26 and 27, located adjacent its upper suitably located clamping nuts and -lower ex remities respectively and extending radia ly thereof, said passages of the section 15 bein adapted to receive upper and lower termmal bolts 28 and 29, the

panel 8 having enlarged openingsto receive the projecting ends of said bolts together with their clamping and terminal nuts.

Each section of the support is exteriorly A provided with a flat Hush surface 30 exten ing about and-between the spaced radial passa es.26 and 27 thereof, and is further provi ed with enlarged portions 31 and 32 located adjacent the medially located passages 20 and 21' thereof; said enlarged rtions serving both to increase the strengt of the respectvesections at such points and also to provide lat surfaces normal te the axes of said latter passages but located below the plane of the respective flush surfaces '30 thus providin a space to receive the clamping nuts of t e studs 24- and 25 within the contour' of such flush surfaces.

Each of said su port sections is furthermore provided Wit a pair of reduced passages 33 and 34 extending in neral parallel with the passa es 20 m5921- aforedescribed and locate adjacent the shoulders 19 and 18 respectively to receive the respective terminal portions of the heating coil 6 and-conduct the same outside the support.

Said terminal portions are in practice preferably bent about the respective clampingv of the bore with? v spective end caps 35 and 36, the end portions of the support being provided with suitable recesses to receive t e respective cli s.

U By the foregoing arrangement t e heating coil 6 is maintained in suitable operative re ation to the element and particularly to those portions of saidelement to be directl influenced thereby, whereas both said coil and said element are entirely surrounded radially by the support 7.

The aforedescribed arran ment is advantageous in securing the desired inverse time element of the device whereby the same is adapted to respond with varyin degrees of dispatch to varying conditions o ener 'zing of the heating coil. Thus, during mo erate overloads of the circuit including said coil, the correspondin values of heat developed thereby7 are dissipated to the surrounding media chiefly by conduction and onl to a relatively sli ht extent by radiation. ence assum' sai coil to be in mechanical contact wit the support 7 but spaced from the tubular extension 10 a relatively large proportion of the heat developed will be absorbed b the support whereas a relatively small va ue of such heat will be applied to the element 5, whereby r onse of said ele ment for interru tion of circuit may be delayed for a relatively long period.

On the other hand assumin 'such an overload of the circuit including t e heating coil as to heat the latter to a comparatively high temperature, a relatively hig pro ortion of the heat develo ed is radiated irectly to the element .5 or eiecting an earlier response thereof for interruption of the cir-` cuit, a relatively small value of theheat bing under these conditions absorbed bythe support, whereas the latter serves to some extent. to direct the radiations toward the extension. The support thus serves both to rolong the time element for moderate overoads and to shorten such time element for heavier overloads.

Also assumin the circuit of the heating coil to be contro lable by the switch element 5, following interruption of such circuit by said element under any of the aforestated conditions the su port 7 may be arranged to retain the heat eveloped by said coil for a relatively long period whereby re-establishlment of the interrupted circuit may be corres ondin ly delayed.

l of ie aforedescribed operative characteristics of the ydevice may be varied or calibrated in numerous ways, as by varying the contour and dimensions of the control element 5 particularly the inner diameter of its restricted passage and of the enlarged portion of such passage to be directly subjected to the action of the heating'coil. Also through variation of the electro-therinic characteristic of the heating coil, or optionally by varying the radial distance of said coil from the tubular extension or from the support either with orwithout interposition of media for varying the conducting and radiating conditions, the character of the response of the device to varying electro-thermic conditions may be regulated throughout exceedingly wide ranges.

Owing to the unreticulated contour of the control element 5 and tothe aforedscribed manner of co-operation thereof with the support 7, it is obvious that the former mav 'be readily removed and replaced with reference to the latter without disassembly of the latter by merely springing back the clip 37, the upper side portions of the support being preferably cut away as indicated at 39 for facilitating such action.

The heating coil 6 is moreover readily accessible upon removal of only the front section of the support. Whereas for removal of the heating coil or inspection of the terminals thereof, the rearwardly located support section may also be readily slippedforwardly from the studs 24 and 25.

Obviously the aforedescribed sectional construction of the support is not absolutely essential herein since the non-embedded and radially removable arrangement of the heater coil 6 is likewise not essential, whereas, assumin the heater coil to vbe non-em- -bedded in t e .support as illustrated, should it be desired to provide a different character of removability of the coil from the support, whether the latter be 'constructed sectional as illustrated or otherwise, the herein disclosed manner of mounting and assembly of the control element 5 with reference to said su port will be at once suggestive to one skilled in the art of ways whereby such result may be attained.

In practice the flush surface 30 of the front support section is preferably covered by a suitable face plate 40 secured thereto by means of short screw bolts 41, eirtenelinor through and closing the passages 26 and 2 thereof, such plate serving to cover the openings of the reduced passages 33 and 34 in said section and lending a neat and finished ap earance to the device.

at I claim as new and desire to secure byLetters Patent is:

1. In a circuit interruptor the combination with a control element comprising a container and a conductor therein which is fluid at working temperature and a heater means extraneous to said conductor for sub.- jecting the latter to action of a fluid under pressure for rendering saidconductor elec'- trically discontinuous, of means for hastening responseo-f said element Within given range of variation of such influence.

' 3. lIn a circuit interrupter the combination with a control element comprising a container and a conductor therein which is fluid at Working temperature and thermalmeans extraneous to said conductor to subject the latter to action of a fluid under Apressure for rendering said conductor electrically discontinuous, of v means adapted Within different ranges of variation of such' ,influence to respectively delay and hasten response of'said element.

4. In a circuit interrupter, the combina- Ation with a control element comprising a container and a conductor therein which is fluid at working temperatures and adapted under thermic influence to be subjected to action of a fluid under pressure for rendering the same electrically discontinuous, of associated means adapted to undergo thermic changes for subjecting said element to such influence and means for delaying revsponse of said element Within a given range of'thermic changes of said former means.

5. In a circuit interrupter, the combination with a controlelement comprising` a container vand a conductor therein which is fluid at Working temperatures and adapted under thermic influence to be subjected to actionof a fluid underV ressure for render-l ing the same electrical y discontinuous, of associated means adapted to undergo thermic changes for subjectingsaid element to such influence and means for hastening response of said element Within a given range of thermicchanges of said former means.

l6. VIn a circuit interrupter, the combination, with a control element comprising a container and a conductor therein which is fluid at Working temperatures and adapted under thermic influence to be subjected to action of a fluid under pressure for rendering the same electrically discontinuous, of associated means adapted to undergo thermic changes for subjecting said element to such influence and means for delaying response of said element Within a given range of thermic changes of said former means and for hastening response of said element Within a different range of thermic changes of saidv former means.

, influence and vunder thermic influence to be subjected to action of a fluid under pressure for rendering the same electrically discontinuous, of

associated means adapted to undergo thermic'- changes for subjecting said element to such influence and heat absorbing means associated with said former means to-vary the degreev or influence of said former means upon said element.

8. In a circuit interrupter, the combination with a control element comprising a container and. a conductor therein which is fluid at Working temperatures and adapted underjthermic influence to be subjected to action of a fluid under ing the saine electrical y discontinuous, of associated means adapted to undergo thermic changes for subjecting said element to such influence and a heat absorbing support for said element and said associated-means, for var ing the responsiveness of' the former un er different thermic conditions ofthe latter.

.9. In av circuit interrupter, the combination with a control element comprising a container and a conductor therein which is fluid at Working temperatures and adapted under thermic`Y influence to be subjected to action of a-fiuid under pressure for rendering the same electrically discontinuous, of associated means adapted to undergo thermic changes for subjecting said. element to such influence and a heat absorbing supportfor said elementand said associated ressure for renderv means,` adapted to absorb different proportionsfof the heat of said associated means under different thermic conditions of the latter for varyingthe degree of influence of said means upon said element.

l0.A In a circuit interrupter, the combination with a control element comprising a container and a conductor therein which is fluid at Workin temperatures and ada ted under thermic influence to be subjecte to action of a fluid under pressure for rendering the saine electrically discontinuous, of a vheating element for subjecting said element to such influence and supporting means for Asaid elements adapted to absorb different proportions of the heat developed by said eating element under different thermic conditions of the latter.

11. In a circuit interrupter, the combination .with a control element comprising a container and a conductor therein lwhich is fluid at workin temperatures and ada ted under thermic influence to be subjecteA to action of a fluid under pressure for rendering the same electrically discontinuous, of a resistor for sub'ecting said element to such eat absorbing supportingV means for said element and said resistor adapted to absorb different proportionate values of the heat developed by said resistor under different conditions of energization of the latter. v

12. In a circuit interrupter, the combination with a control element comprising a container and a conductor therein which is liquid at Working temperatures and adapted under thermic influence to be subjected to action of a fiuid under -pressure for effecting electrical discontinuity thereof, ofmeans for subjecting saidelement to such iniiuence and common means for independently supporting said element and said former means in co-o erative relation to one another. 13. n a cireuitfinterrupter, the combination with a control element comprising a container having a restricted tubular extension and a' conductor which is liquid at working temperatures filling said extension and adapted under thermic influence to be rendered electrically discontinuous, of a heating coil surrounding said extension for so influencing the conductor contained therein and joint supporting means for said element and said coil comprising a 'body of heat absorbing material surrounding said coil and said extension to absorb different proportionate values ofthe heat developed by said coil dependent upon the degree of energization of the latter.

14. The combination with an insulating support having an opening therein. of aA control element readily insertable within said opening and removable therefrom and terminal means forsaid element, said elevment comprising a container and a contemperatures and adapted under thermic' infiuence to `be subjected to action of its own vapor under pressure for effecting elec- I trical discontinuity thereof.

15. The combination with an insulating support having an opening therein of a control element readily insertable within said opening and removable therefrom, said element comprising a container and a conductor therein which is liquid at working temperatures and ada ted under thermic influence to be subjecte to action of itscown va or under pressure for effecting electrical iscontinuit thereof, means for so infiuencing said con uctor and terminal means for said element carried by said'sup ort.

16. The combination wit a control element comprising an insulating container having a restricted'tubular extenslon and a conductor which is li uid at working temperatures located .withm said extension and adapted under thermic influence to be rendei-ed electrically discontinuous, electrodes carried by said container and in electrical connection with the conductor contained therein, conductive members carried exteriorly of said container and in electrical connection with said electrodes, terminal devices carried by said support and conductive clips for connecting said terminal de-` vices with the respective eXteriorly located conductive elements of said unit, said clips serving`for positioning and retention of said element within said support and means for subjecting said element to thermic influence for interrupting the electrical connection between said terminal devices.

17. The combination with a control element comprising a' container and a conductor therein which is liquid at working temperatures and adapted under thermic influence to be subject to action of its own va or 'under pressure for efecting electrical iscontinuity thereof of a support for said element having an opening for ready insertion andV removal of said element, said support comprising separable and interchangeable sections and common means for clamping said' sections in assembled relation and for mounting said support upon a suitable base.

18. In a circuit interrupter, the combination with a control element comprising a container and a conductor therein which is fluid at working temperature and adapted under thermic influence to be subjected to action of a fluid under pressure for effecting, selectively, interruption and restoration, of electrical continuity of said conductor, of means for` delaying response of said element within a given range of variation of such influence.

19. In a circuit interrupter, the combination with a'control element comprising a container and a conductor therein which is fluid at working temperature and adapted under thermic influence to be subjected to action of a fiuid under pressure for effecting, selectively, interruption and restoration of electrical continuity of said conductor, of means for delaying response of said element, both for interruption and for restoration of continuity, within given ranges of variation 0f such infiuence.

20. In a circuit interrupter, the combination with a control element comprising a container and a conductor therein which is fluid at working temperature and ada ted under thermic influence to be subjecte to action of a -fluid pressure 4of its own vapor for eiiz'ecting, selectively, interruption and restoration of electrical continuity of said conductor, of means for delaying response of said element within a given range of variation of such influence.

In witness whereof, I have hereunto subscribed my name.

ERWIN R. STOEKLE.

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